Orthomyxovirus

1. The most prevalent human virus causing most of human epidemics is
a) Influenza A
b) Influenza B
c) Influenza C

2. Ag found free in infected tissues
a) M protein
b) HA
c) Ribonucleoprotein
d) NA

3. Ag that destroys Sialic acid receptors on cell surface during exit
a) M protein
b) HA
c) Ribonucleoprotein
d) NA

4. Ag which promotes release and spread of progeny virions
a) M protein
b) HA
c) Ribonucleoprotein
d) Neuraminidase

5. Influenza virus causes cell death by all of the following except
a) Direct effects of virus on the cell
b) Action of helper T cells
c) Action of cytotoxic T cells
d) Action of Interferons

6. The following are true about antigenic variation in influenza except:
a) Highest variability in type A
b) None in type C
c) Some variability in type C
d) HA and NA undergo independent antigenic variations


Answers:

1. (a) 2. (c) 3. (d) 4. (d) 5. (b) 6. (c)